The Australian Communications and Media Authority (ACMA) has come to a compromise on the decision to allocate spectrum for public safety agencies (PSAs), granting them half of the spectrum from the 800MHz band that they asked for, but providing an additional 50MHz from the 4.9GHz band.

PSAs have been arguing for the need for emergency spectrum for some time, with Motorola Solutions originally battling for 20MHz of spectrum out of the 700MHz band. According to the company, this would be on par with other PSAs in the US, and would assist with keeping equipment costs down by using the standardised band.

The digital dividend, which will free up 126MHz of spectrum in the 700MHz band, would have been an ideal opportunity for PSAs to make their claims to dedicated spectrum. However, the Australian government raised the alternative of using the 800MHz spectrum and some PSAs relented, as equipment could be upgraded or modified to work on the new frequency.

However, the ACMA has dedicated just two 5MHz segments out of the 800MHz band to emergency services, determining from its own analysis of the forecasted demand on the network that "2x 10MHz would, for all but rarely occurring emergency events, be largely under-used, and that 2x 5MHz was sufficient for day-to-day, pre-planned, and most emergency use."

The ACMA is not leaving PSAs empty handed, however. In a compromise, the ACMA will provide PSAs with an additional 50MHz of spectrum from the 4.9GHz band for "spill-over capacity during major events that result in radio traffic that exceeds the capacity in the 800MHz band." The ACMA has argued that this spectrum will still provide the benefits of being able to use international equipment, arguing that the band is "recognised internationally as a frequency band for use by public safety and other emergency response services."

"It is capable of extremely high-capacity, short-range, instantly deployable data and video communications. This represents a supplementary capacity for the public safety mobile broadband network in areas of very high demand."

In addition, the ACMA argued that that the cost difference between equipment made for different spectrums is minimal. Nevertheless, the ACMA has said that it will continue to work with PSAs on whether it is appropriate to license further spectrum in the 800MHz band.

The ACMA also said that its decision took into account claims that emergency services could be provided over commercial telecommunications companies' existing infrastructure. Telstra has previously argued that its 4G network would be better suited for an emergency network, but the ACMA has dismissed the suggestion on advice previously provided by PSAs.

"They informed us telco infrastructure cannot necessarily be relied on in emergencies, and that they would need their own frequencies operating on their own, hardened infrastructure to guarantee availability in a wide range of operational scenarios."